Current Issue : April - June Volume : 2012 Issue Number : 2 Articles : 7 Articles
An application of a robotic system integrated with a vision system is presented. The robot is a 3-axis revolute prototype, while\r\nthe vision system essentially consists in a laser scanner made up of a camera and a linear laser projector. Both the robotic and\r\nthe video system were designed and built at DIME (Department of Mechanical Engineering for Energetics), University of Naples\r\nFederico II. The presented application essentially consists of a laser scanner that is installed on the robot arm; the scanner scans\r\na 3D surface, and the data are converted in a cloud of points in the robot�s workspace. Then, starting from those points, the endeffector\r\ntrajectories adopted to replicate the scanned surface are calculated; so, the same robot, by using a tool, can reproduce the\r\nscanned object. The software was developed also at the DIME. The adopted tool was a high-speed drill, installed on the last link of\r\nthe robot arm, with a spherical milling cutter in order to obtain enough accurate surfaces by the data represented by the cloud of\r\npoints. An algorithm to interpolate the paths and to plan the trajectories was also developed and successfully tested....
This paper discusses the design and steering control for an autonomous modular mobile robot. The module is designed with a\ncenter-articulated steering joint to minimize the number of actuators used in the chain.We propose a feedback control law which\nallows steering between configurations in the plane and show its application as a parking control to dock modules together. The\ncontrol law is designed by Lyapunov techniques and relies on the equations of the robot in polar coordinates. A set of experiments\nhave been carried out to show the performance of the proposed approach. The design is intended to endow individual wheeled\nmodules with the capability to merge and make a single snake-like robot to take advantage of the benefits of modular robotics....
Design of an adaptive controller for complex dynamic systems is a big challenge faced by the researchers. In this paper, we introduce\r\na novel concept of dynamic pole motion (DPM) for the design of an error-based adaptive controller (E-BAC). The purpose of this\r\nnovel design approach is to make the system response reasonably fast with no overshoot, where the system may be time varying and\r\nnonlinear with only partially known dynamics. The E-BAC is implanted in a system as a nonlinear controller with two dominant\r\ndynamic parameters: the dynamic position feedback and the dynamic velocity feedback. For illustrating the strength of this new\r\napproach, in this paper we give an example of a flexible robot with nonlinear dynamics. In the design of this feedback adaptive\r\ncontroller, parameters of the controller are designed as a function of the system error. The position feedback Kp(e,t) and the velocity\r\nfeedback Kv(e,t) are continuously varying and formulated as a function of the system error e(t). This approach for formulating the\r\nadaptive controller yields a very fast response with no overshoot....
This paper presents a new type of finger rehabilitation system using amultifingered haptic interface that is controlled by the patient\r\nthough a surface electromyogram.We have developed themultifingered haptic interface robot: HIROIII that can give 3-directional\r\nforces to 5 fingertips. This robot can also be used as a rehabilitation device that can provide various fingertip exercises and measure\r\nvarious types of information. The sEMG works together with the HIRO III to consider the patient�s intent. The proposed system\r\nis intended for patients having paralysis in the hand and fingers, and the motions will be provided as biofeedback to the fingertips\r\nwith the device. In contrast to completely passive rehabilitation, the proposed system can provide active rehabilitation using sEMG.\r\nThe experiment involved finger opening and closing with this system by ten able-bodied subjects. The results show that almost all\r\nsubjects felt appropriate motion support from the device....
We have developed a universal robot hand with tactile and other sensors. An array-type tactile sensor is crucial for dexterous\r\nmanipulation of objects using a robotic hand, since this sensor can measure the pressure distribution on finger pads. The sensor\r\nhas a very high resolution, and the shape of a grasped object can be classified by using this sensor. The more the number\r\nof measurement points provided, the higher the accuracy of the classification, but with a corresponding lengthening of the\r\nmeasurement cycle. In this paper, the problem of slow response time is resolved by using software for an array-type tactile sensor\r\nwith high resolution that emulates the human sensor system. The validity of the proposed method is demonstrated through\r\nexperiments....
Navigation robotsmust single out partners requiring navigation and move in the cluttered environment where people walk around.\nDeveloping such robots requires two different people detections: detecting partners and detecting all moving people around\nthe robots. For detecting partners, we design divided spaces based on the spatial relationships and sensing ranges. Mapping the\nfriendliness of each divided space based on the stimulus from the multiple sensors to detect people calling robots positively, robots\ndetect partners on the highest friendliness space. For detecting moving people, we regard objects� floor boundary points in an\nomnidirectional image as obstacles. We classify obstacles as moving people by comparing movement of each point with robot\nmovement using odometry data, dynamically changing thresholds to detect. Our robot detected 95.0% of partners while it stands\nby and interacts with people and detected 85.0% of moving people while robot moves, which was four times higher than previous\nmethods did....
Most of the present work for unmanned surface vehicle (USV) navigation does not take into account environmental disturbances\r\nsuch as ocean waves, winds, and currents. In some scenarios, waves should be treated as special case of dynamic obstacle and can\r\nbe critical to USV�s safety. For the first time, this paper presents unique concept facing this challenge by combining ocean waves�\r\nformulation with the probabilistic velocity obstacle (PVO) method for autonomous navigation. A simple navigation algorithm is\r\npresented in order to apply the method of USV�s navigation in presence of waves. A planner simulation dealing with waves and\r\nobstacles avoidance is introduced....
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